Watch-case spring



W. DRYSDALE. Watch-Case Spring.

No. 227,504; Patented May 11, 1880.

UNITED STATES WILLIAM DRYSDALE, OF

PATENT OFFICE.

LOUISVILLE, KENTUCKY.

WATCH-CASE SPRING,

SPECIFICATION forming part of Letters Patent No. 227,504, dated May11,1880,

Application filed October 15, 1870.

To all whom it may concern Be it known that I, WM. DRYSDALE, ofLouisville, in the county of Jefferson, and in the State of Kentucky,have invented certain new and useful Improvementsin VVatch-Gases and Ido hereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawings,making a part of this specification, in which Figure l is a perspectiveview of my improved case hinge and spring separated from each other andfrom the case. Fig. 2 is a like View of said parts in position within acase. Fig. 3 is an elevation from the inner side of said parts. Fig. 4is a perspective view of the catch piece and spring separated from eachother and from the case. Fig. 5 is an elevation from the inner side ofsaid parts, and Fig. 6 is a plan View of said springs.

Letters of like name and kind refer to like parts in each of thefigures.

The design of my invention is to render a watch-case dust-proof at thepoints where the case-spring and catch-piecepass outward and to this endit consists, principally, in a shut spring and catch-piece made separatefrom each other and adapted for connection after the former is in placewithin the case, substantiallyas andforthe purpose hereinafter shown.

It consists, further, in a shut-sprin g provided with a lug whichreceives the catch-piece and incloses from below the opening in thecasecenter through which said catch-piece passes inward, substantiallyas and for the purpose hereinafter set forth.

It consists, finally, in the construction of the shut-spring andcatch-piece and their combination with each other and with the case,substantially as and for the purpose hereinafter shown and described.

In the annexed drawings, A represents a case-center provided with afront, 13, and bezel 0, each of which latter parts is hinged to or uponsaid case-center in the usual manner.

From the hinge portion of the case-front B a lug or arm, 1), extendsinward in a curved line, of which the axis of the hinge is the ce11-ter. Said arm is rectangular in cross-section and closely fills theopening a in said case-ecu arm is above the line to which the edge ofthebezel O shuts down, a notch, c, is provided within the latter for thepassage of said arm. The inner end of the arm I) is hollowed out, asshown in Fig. 1., and fits over and engages with the end (I of acase-spring, D, which has the usual form, except that its free end disstraight and round, instead of having the usual outward-projectinglugfor engagement with the hinge of the case-front. If, now, the casefrontB is closed, the curved arm 1) moves the free end (1 of the spring Drearward and downward, instead of giving to said spring a twistingstrain, as in case of springs of ordinary construction, by which meansthere is less than usual liability to injury and breakage, while fromthe lllUlBiLSGil leverage upon said case-"front, secured by use of thecurved arm, the joint is never strained, and receives none of the usualwear that is occasioned by the end of the spring of ordinary form.

In consequence of the concentric form with relation to the hinge-axisgiven to the arm I), it may be caused to fit so closely within theopenings a and c at all points of its movement as to effectually preventdust from passinginto the interior of the case at such point.

The shut-spring E has the form shown in Fig. 4, its rear end beingfitted to the concavity of the inner side of the case-center A, andprovided with the usual threaded opening 0 for the reception of afastening'screw, c. From the thick rear portion of said spring to itsfront end it is made thin, as shown, and at a point near said front endis provided with a lu c that has a s nare form in )lan view and isprovided with a threaded opening that receives the threaded shank f of acatch-piece, F, which above said shank has the usual form.

In use, the spring E is placed within and secured to the casecenter inthe usual manner, with its lug 0 directly beneath the opening a, that isprovided within the inward-projectin g flange of said case-center forthe passage of the shank of the catch-piece F, said lug being arrangedto bear against the lower side of said flange, and, having horizontallyconsiderablylarger dimensions than said opening, effecttually closes thelatter against the passage of dust. The catch-piece is now placed inpositer which is provided for its passage. As said 1 tion by screwingits shank f into the lug 6 atter which said parts operate in the usualman-.

ner. The projecting outer end of the spring E receives the inner end ofthe push-pin G, and enables the latter to move said spring inward in theusual manner.

By use of my case-spring and shut-spring a watch-ease maybe made soclose as to prevent the inward passage of dust, and to renderunnecessary the various expensive methods for inclosing the movement andrendering the same dust-proof.

Having thus fully set forth the nature and merits of my invention, whatI claim as new is 1. A shut-spring and catch-piece made separate fromeach other and adapted for connection after the former is in placewithin the ease, substantially as and for the purpose shown.

2. A shut-spring provided with a lug which receives the catch-pin andineloses from below the opening in the case-center through which saidcatch-pin passes inward, substantially as and for the purpose set forth.

3. The shut-spring E, provided with the lug e and the catch-piece Fhaving a threaded shank f, in combination with each other and with theease-center A, substantially as and for the purpose shown and described.

In testimony that I claim the foregoing I have hereunto set my hand this4th day of October, 1879.

WM DRYSDALE.

W'itnesses: a

W. KENDRIeK, FE. AL. ZUMAR.

